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2 Sheets-Sheet. l.

(No Model.)

W. H. JOHNSN.

HYDRAULIC LIFT.

No. 311,327'. Patented Jan. 2?, 1885.

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(No Model.) 2 Sheets-Sheet 2.

- W. H. JOIVINSOlJ.I

HYDRAULIC LFT.

No. 311.327. Patented Jan.. 27, 1885n F'ICMvA nire rares VILLIAM HUMBLE JOHNSON, OF W'ESTMINSTER, OOUNTSLT OF MIDDLESEX, ASSIGNOR TO EDW'ARD BAYZAND ELLINGTON, OE CHESTER, ENGLAND.

HYDRAULIC LIFT..

@PECIFECATION forming part of Letters Patent No. 311,327, dated January 27, 1885.

Application lfed Norcmber 24. i883. (No model.) Patented in England March 12, 1882i, No. 1,325.

T0 @ZZ whom t may concern:

Be it known that I, WILLIAM HUMBLE JOHNSON, a citizen of England, residing at Vestminster, in the county of Middlesex, England, have invented an Improvement in Hydraulic Lifts, (for which have obtained a patentin Great Britain, No. 1,325, bearing date March 13, 1883,) of which the following is a specification.

It has been proposed to employ hydraulic pressure instead oi' counter-weights for balancing so much as is necessary of the weight of the cages and plungers of hydraulic lifts, and this has been eifected by arranging auxiliary cylinders to communicate` with the lift-cyliir ders, and to have their pistons or plungers acted on by such pressures as are necessary to impart the required pressure to the contents of the litt-cylinders, and thereby to the plun gers of the lifts. As the counter-balance requires in each case to be increased the more the lift-plunger protrudes from its cylinder, these auxiliary cylinders have been so ar ranged that the pressure-columns acting in them shall increase proportionally to the ascent of the lift-plungers and decrease proportionally to their descent, and thus the lift cages and plungers can be uniformly counterpoised at all parts of their stroke.

My invention relates to a construction and arrangement of such hydraulic counterpoising and compensating apparatus, whereby I am enabled to simplify their construction, to economize space for their accommodation, and to obtain facilities for erection and for repair when necessary. For this purpose l make the counterbalaneing cylinders and plungers of the annular kind surrounding the lift-cylinder and its plunger, so that thel whole apparatus is accommodated on one foundation within the space of the lift-shaft, and without requiring external pipe-connections.

The particular arrangements of the counterbalancing cylinders and plungers may be varied to suit various conditions. l will describe several arrangements as examples of the constructions which I adopt, referring to the accompanying drawings, in which Figures l, 2, 3, 4, 5, and 6 are vertical sections, showing in each case part of the lift-cylinder A and plunger B with hydraulic balancing apparatus according to my invention.

Fig. 1 shows an arrangement that may be used when it is desired to intensify the servicepressure so as to have a greater pressure 5 5 acting in the lift-cylinder. ln this case part of the lift-cylinder A, which is closed at its lower end and extends down into a well, as is common with lifts of this character, at A A2 is made of differential arca, and on it works an annular plunger, C, sufficiently heavy in itself, or loaded sufliciently to counterbalance the weight ofthe lift plunger and cage or any desired portion thereof. The differential space of the plunger O, when it is at the extreme of its upstroke, has capacity enough to contain all the liquid required to raise the lift-plunger B. Passages at a make communication between the lift-cylinder and the interior of the plunger C. municates at d, through a suitable valve-box, which may be of any ofthe ordinary and wellknown forms, and therefore not shown, with the accumulator or supply-reservoir and with the discharge, as usual; and the plunger O works through packing at the bottoni of D. On admitting the liquid under pressure to D, the plunger O is forced downwarchand, owing to the difference of area of A and A2, liquid at increased pressure is forced through a from the S0.

interior of O into the lift-cylinder A, raising the plunger B and the cage.- As by the descent of O the column offliquid pressing on it in creases proportionally to the ascent of the plunger B, the variation of load due to the greater or less protrusion of B is compensated throughout the stroke. On opening d to the discharge, the weight of the cage and plunger B causes them to descend, forcing liquid through a into O and causing C to rise. the arrangement shown in Fig. 2 the hollow plunger C works through packing not onlyin the cylinder D, but also in a lower cylinder, E, communicating at c with the lift-cylinder A, the lift-cylinder being divided at such point for that purpose, the lower section or portion of the liftcylinder in such construe tion being indicated in Figs.'2 to 6 by the letter A3. In this case the liquid of course passes i into the cylinder E before entering the upper ico A stationary cylinder, D, com 70 In 9e portion of the lift cylinder. A passage, c, leading to theinterior of O, will be in constant communication with the accumulator or pressure-reservoir, so that,in addition to the weight .of C, this pressure acts as counter-balance, d

being, as before, in communication with the supply and discharge valve box. Obviously the connections of c and d may be inverted, cl being in constant communication with the accumulator, while c communicates with the valve-box.

In further explanation of the operation of the construction illustrated in Fig. 2, it may be added that,`c being in constant communication with the pressure-reservoir, this pressure, acting within C on the difference ofarea between Al2 and A and tending to force C down, forms practically an addition to the weight of C, operating as a counter-balance to the cage and plunger. New, when pressure is v admitted at d, this pressure adds still further to serves, in addition to the downward force on O, making it descend. By the descent 0f C the water in E is forced through-a into A, causing B to ascend. Vhen the pressure is relieved by opening d to discharge, the weight of the cage and plunger sends back the water from A into E, causing Oto rise, and the ascent of C causes the water within itself to flow back by c to the reservoir. Byinverting the connections of c and fZ-that is, connecting d to the reservoir and c to the valve-hoX-the pressure in D acts on O outside of it, as a constant addition to its weight, and when C is opened to the reservoir there is the additional pressure brought to act inside C, so that the action is similar to that described. By a modication of this arrangement (shown in Fig. 3) a low-pressure supply, constantly communicating with I) through d and acting on the enlarged piston-area of C, the weight of C, for counter-balance, the working being effected by supply and discharge through c, the same as described for Fig. 2.

Fig. 4 shows another modification of the arrangement shown in Fig. 2, the parts in this case being so arranged that the plunger C works on the lift-plunger B, the only difference between the action of the parts shown in Figs. 2 and 4 being that in Fig. 2 the pressureadmitted by c acts inside of C, whereas in Fig. 4- it acts on the annular piston area at the lower end of C. As in Fig. 2, so in Fig. 4, either c or d may constantly communicate with a pressurereservoir, the other of them being connected to the valve-box. In the arrangement shown ,to be in one piece.

in Fig. 5 Weights W, placed on C, serve for counter-balance, the working being effected through the passage ci. By the arrangement shown in Fig. 6, C is made of sufficient weight or is loaded sufficiently for counter-balance, the working being effected by high-pressure liquid through cl. The weight of C itself being sufficient for counter-balance, this weight produces within the cylinderE sufficient pressure to act on the area of B to overcome as much of the weight of the cage and plunger as may be necessary.

In Figs. 4, 5, and 6 the upper portion of the lift-cylinder is formed by the passage through the plunger or piston C, so that such part of the .lift-cylinder and the plunger may be said rlhe operation of such parts, however, is the same in principle and so apparent to the skilled in the art that a detailed description of each would be a repetition, and therefore further description is not given.

Having thus described the nature of my invention and the best means I know of carrying it into practical operation, I would have it understood that I make no general claim to counterpoising thev cages and plungers of hydraulic lifts by hydraulic pressure, nor to the application of the pressure in such a manner as to compensate for the greater or less protrusion of the lift-plungers; but

I claim in respect of hydraulic lifts to which such hydraulic counterpoising and compensating apparatus is appliedl. rIhe combination, with the central liftcylinder and lift-plunger of a hydraulic lift, of a vertically-moving counterbalancing-plunger surrounding the lift-cylinder, and a cylinder surrounding said counterbalancing-plunger, substantially as described.

2. The combination, in a hydraulic lift, of the lift-cylinder and liftplunger with the counterbalancing hollow plunger annularly surrounding the lift-cylinder and plunger and movable vertically thereon, and the cylinder for the counterloalancing plunger also surrounding the lift cylinder and plunger, substantially as described.

In testimony whereof Ihavc signed my name to this specificatiomin the presence oftwo subkscribing witnesses, this 6th day of November,

' WM. I-IUMBLE JOHNSON. lVitnesses:

OLIVER IMRAY, JN0. l?. M. MILLARD.

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